Bubble hair is an acquired hair shaft abnormality characterized by multiple airfilled spaces within the hair shaft. It is a result of thermal injury. We report a classic case of 22-year-old female who complained of dry brittle hair of two-week duration. Patient had used hot iron on wet hair twice to straighten hair. Hair microscopy was diagnostic and showed multiple air-filled spaces within the hair shaft.

Bubble hair is an acquired hair shaft deformity characterized by bubble-like areas in the hair shaft seen with light microscopy and corresponding cavitary defects with scanning electron microscopy. [1] It occurs due to thermal injury caused to the hair by hair dryers, heating tongs or hot curls. Hair appears dry, wiry, with patchy loss of hair due to excessive fragility. It may be associated with other acquired hair shaft defects such as trichorrhexis nodosa and trichoptilosis.

Case Report

A 22-year-old female patient reported to us with complaints of dry hair with excessive fragility of two-week duration. There was history of using hot iron on wet hair to straighten the hair twice over the past one month. There was no history of using chemicals or any other procedures.

There were no similar complaints in the past. There was no family history of similar complaints. Clinical examination of scalp hair showed dry brittle hair which was broken unevenly [Figure 1] and [Figure 2]. There was no patchy loss of hair. Eyebrows and body hair was normal. Hair was not easily pluckable but was brittle.

Light microscopic examination of the hair showed spaces within the hair shaft [Figure 3]. Few hairs showed node-like formation with fraying (Trichorrhexis nodosa) and there was distal splitting of hair (Trichoptilosis) [Figure 4] and [Figure 5]. These changes were noted in other hair samples and not the one which showed bubbles.

Brown et al. published the first report of bubble hair in 1986. [2] As the name suggests, bubble hair is full of bubbles much like a sponge. [3]

Bubble hair is a sign of thermal injury. Hair dryers operating at 175°C or more can cause bubble hair. The use of hair curling tongs operating at 125°C and applied to the hair for one minute can also induce bubbles in hair fiber. [1] All hair fibers contain air-filled spaces called vacuoles. These spaces can also become filled with water when the hair is wet. Too much heat vaporizes the water in the hair fibre into steam. This vaporization of the water may force the spaces in the hair to expand, eventually turning the hair into a sponge-like structure. These damaged hairs are weak and brittle as the bubbles destroy the integrity of the fiber. [4] Chemical treatment may also precipitate the onset of bubble hair and any already weak hair, whatever the cause, may be more susceptible to bubble development. [3]

Electron microscopic studies of previously reported cases revealed a loss of cortical cells and medulla at these sites. Cross-section images showed either a single large cavity or a reticulated, "swiss cheese-like" loss of cells. [5]

Under dermatoscopy, dysmorphia of distal hair shaft was observed in bubble hair. In large hair samples, dermatoscopy can be used to highlight hair that warranted closer examination under light microscopy. [6]

Clinically, hair appears to be kinked, break off, and over time, the condition may develop into a localized alopecia. The hair appearing to "come out in clumps," and the overall texture of the hair changing from soft and naturally curly to straight and stiff has been reported. [2] Bubble hair is a reproducible hair shaft disorder caused by thermal injury. It can be prevented and treated by avoidance of using excessive heat and chemicals on the hair and by cutting off the old damaged hair.

Our case presented with a classical history of use of hot irons to straighten hair followed by hair changes. Along with bubble hair, other shaft abnormalities like trichoptilosis and trichorrhexis nodosa were also noted. There are a few reports of bubble hair in literature. [2],[3],[4],[7]

Though it is a common condition, it is rarely diagnosed and reported. Light microscopic examination is sufficient to make a diagnosis and counseling the patient will prevent repeated injury to hair shaft.